It is common for an owner of a vehicle, such as an automobile, truck or the like, to tow or trail various trailers, such as a camper trailer, a boat trailer, a storage trailer, or the like. Electrical power is made available to the trailer by means of an electrical wire connector electrically connected to the towing vehicle's electrical supply system. Vehicle electrical connectors can be made to accommodate connection between the various trailers and the vehicle. For example, the Society of Automotive Engineers (SAE) has promulgated a standardized connection scheme that allows for intermixed connection between various types of vehicles and trailers.
In some vehicles, a standardized connection scheme includes two vehicle electrical connectors to allow for intermixed connection between the vehicle and two mutually exclusive trailer connectors. For example, a four pin vehicle electrical connector is provided for lighter duty trailers and a seven pin vehicle electrical connector is provided for heavier duty trailers. Three common circuits between the four and seven pin connectors are Right Turn Stop, Left Turn Stop and Running Lights. The three common circuits are hardwired on the vehicle with a current rating set to heavy duty, seven pin connector drive needs. This leaves the four pin electrical connector and light duty trailer system prone to overload conditions that can damage the connector terminals and the trailer wiring.
To ensure that the proper levels of current are supplied to each of the various trailers, a vehicle electrical connector circuit is provided that regulates current to each output of the two vehicle electrical connectors. As shown in FIG. 1A and according to various aspects of the prior art, a connector circuit 10a provides a fuse 12 and a relay 14 that is controlled by a microprocessor or low current switch 20a to ensure that the current level provided to outputs 16 and 18 from a power source 22 does not exceed a predetermined current level. As shown in FIG. 1B and according to various aspects of the prior art, a connector circuit 10b provides a transistor 24 and 26 for each output 16 and 18 respectively. The transistors 24 and 26 are individually controlled by a microprocessor 20b to ensure that the current level provided to the outputs 16 and 18 from the power source 22 does not exceed a predetermined current level. Implementing separate transistors 24 and 26 or a fuse 12 and a relay 14 for outputs 16 and 18 can be costly.